Esophageal monitoring

ABSTRACT

An esophageal monitoring device includes a camera and, optionally, one or more lights to enable visualization of an interior of a subject&#39;s esophagus. Visualization of the interior of the subject&#39;s esophagus before and after a left atrial ablation procedure may enable a healthcare provider to determine whether or not the left atrial ablation procedure has damaged the subject&#39;s esophagus before the subject experiences any symptoms of such damage. An esophageal monitoring device may also include sensors and/or markers that enable a determination of its location within a subject&#39;s esophagus. Such an esophageal monitoring device may be configured for three-dimensional mapping, and enable the generation of an accurate three-dimensional map of the physical relationship between a subject&#39;s esophagus and the left atrium of his or her heart. Methods of monitoring a subject&#39;s esophagus while a left atrial ablation procedure is being conducted on the subject&#39;s heart are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.15/625,929, filed Jun. 16, 2017, titled ESOPHAGEAL MONITORING (“the '929Application”), issued as U.S. Pat. No. 11,033,232 on Jun. 15, 2021,which claims the benefit of priority to the Jun. 16, 2016 filing date ofU.S. Provisional Patent Application No. 62/350,833, titled ESOPHAGEALMONITORING (“the '833 Provisional Application”) under 35 U.S.C. §119(e). The entire disclosures of the '833 Provisional Application andthe '929 Application are hereby incorporated herein.

TECHNICAL FIELD

This disclosure relates to esophageal monitoring, as may be conductedwhile conducting an ablation procedure on the left atrium of a subject'sheart. More specifically, this disclosure relates to esophagealmonitoring methods that occur in conjunction with visualization of theesophagus. Even more specifically, a subject's esophagus may bevisualized before and after an ablation procedure has been conducted onthe left atrium of the subject's heart. In addition, this disclosurerelates to esophageal monitoring systems and to esophageal monitoringdevices.

RELATED ART

A variety of techniques have been developed in which tissues or organsin a patient's body are heated or cooled. Tissues may be heated by avariety of techniques, including high frequency ultrasound,radiofrequency (RF) treatments, laser treatments, use of infraredradiation, and by direct application of thermal energy. Cooling is ofteneffected cryogenically. Techniques that heat and cool tissues may becollectively referred to as “thermal techniques.”

Thermal techniques are useful for treating a variety of disease states.The degree of heating or cooling that is required to optimize theefficiency of some thermal techniques may adversely affect tissues ororgans that are adjacent to a treated tissue or organ. For example, agreat deal of heat is generated by radiofrequency (RF) waves whenelectrophysiological ablation techniques are used to remove faultyelectrical pathways from the hearts H of human subjects who are prone todeveloping cardiac arrhythmias, such as fibrillation in the left atriaLA of their hearts H. In addition to heating and treating the diseasedtissue in the heart H, the esophagus E, which is located close to theleft atrium LA of the heart H, as shown in FIG. 1 , may also be heated.

As FIG. 1 illustrates, a typical human esophagus E typically has anarrow, or flat, oval cross-sectional shape, taken along a length of theesophagus E, that resembles a pancake, with a large portion of the outersurface of the esophagus E located between the posterior wall of theleft atrium LA (i.e., the location where ablation procedures aretypically conducted in the left atrium LA) and the vertebral column VC,although the size, shape, and/or position of the esophagus E may vary.In an average human adult, about 70 mm of the length and the majority ofthe front side of a 18 mm width of esophagus E is located in proximityto or contacts the posterior wall of the left atrium LA. As aconsequence of the intimate arrangement between the esophagus E and theleft atrium LA, the heat generated during ablation of the left atrium LAmay damage the esophagus E and may, in some cases, create an esophagealfistula. Unfortunately, the complications that arise from esophagealfistula may not present themselves until weeks after the left atrialablation procedure and, in many cases, at too late a time to treatand/or cure the sometimes fatal damage that has been done.

In recognition of the potentially dire consequences of overheating theesophagus E during ablation of the left atrium LA, physicians havestarted using devices that monitor temperature within a subject'sesophagus E during left atrial ablation procedures. If the sensedtemperature reaches a predetermined level, the physician may momentarilydiscontinue the left atrial ablation procedure to allow the esophagus Eto cool and, hopefully, to prevent any damage to the esophagus E.

The use of temperature probes has been shown to reduce or eliminate thedamage, including the formation of one or more fistulas, that couldotherwise be incurred by the esophagus E as ablation procedures arebeing performed on the posterior wall of the left atrium LA of the heartH. Nevertheless, healthcare providers typically do not receive anyfeedback regarding the usefulness of temperature probes unlesscomplications arise from damage caused to the esophagus E by the leftatrial ablation procedure. Again, that damage may not present itself fordays or weeks and, by the time it does present itself, it may not becorrectable.

SUMMARY

A method for monitoring an esophagus of a subject, or “esophagealmonitoring,” during ablation of the left atrium of the subject's heartincludes visualizing the esophagus after the left atrial ablationprocedure, while removing an esophageal monitoring device from thesubject's esophagus. In some embodiments, the esophagus may also bevisualized while inserting the esophageal monitoring device into theesophagus.

A method for esophageal monitoring according to this disclosure may beperformed as part of a procedure for ablating faulty electrical pathwaysin the posterior wall of the left atrium; i.e., left atrial ablation. Insuch a method, an esophageal monitoring device may be introduced into asubject's esophagus prior to ablation of the posterior wall of the leftatrium. In some embodiments, the esophagus and its condition prior tothe left atrial ablation procedure may be visualized and optionallyrecorded as the esophageal monitoring device is introduced into theesophagus. With the esophageal monitoring device in place against aninner surface of a portion of the esophagus that is located in proximityto the posterior wall of the left atrium, the posterior wall of the leftatrium may be ablated. During left atrial ablation procedure, theesophageal monitoring device is used to monitor the inner surface of theportion of the esophagus against which the esophageal monitoring devicehas been placed. Once the left atrial ablation procedure is complete,the esophageal monitoring device may be removed from the esophagus. Asthe esophageal monitoring device is removed from the esophagus, theesophagus and its condition following the left atrial ablation proceduremay be visualized and optionally recorded. As used herein, the term“visualize” includes obtaining images (e.g., still images, video images,etc.) of the inner surface of the esophagus and making the imagesavailable to a healthcare provider for viewing. Viewing of the imagesmay occur contemporaneously with introduction of the esophagealmonitoring device into the esophagus and/or with removal of theesophageal monitoring device from the esophagus. Alternatively, theimages may be viewed at a later time (e.g., after completion of the leftatrial ablation procedure, etc.).

Visualization of the esophagus during insertion of the esophagealmonitoring device or during removal of the esophageal monitoring devicemay be accompanied by position reference monitoring, in which theposition of the esophageal monitoring device relative to the esophagus(e.g., a depth the esophageal monitoring device has been inserted intothe esophagus, etc.) is periodically determined. Position referencemonitoring may include sensing position reference features on aninsertion component (e.g., a catheter, another tube, etc.) for theesophageal monitoring device or on the esophageal monitoring device asthe position reference features pass one or more fixed locations. Morespecifically, position reference monitoring may occur as positionreference features move past one or more position sensors, which may belocated at substantially fixed locations relative to the subject'sesophagus (e.g., at a location outside the subject's body in embodimentswhere the position reference features are carried by the insertioncomponent or the esophageal monitoring device, along a length of aninsertion component in embodiments where the position reference featuresare carried by the esophageal monitoring device, etc.). The positionreference features may be spaced at various intervals (e.g., 5 mm, 1 cm,etc.) along a length of the insertion component or the esophagealmonitoring device (e.g., a proximal element of the esophageal monitoringdevice, etc.). In embodiments where visualization of the inner surfaceof the esophagus includes capturing still images of the esophagus, aseach position reference feature passes the position sensor, the positionsensor or the position reference feature may cause a camera carried bythe esophageal monitoring device to capture a still image, synchronizingeach image with the depth, or location, of the esophageal monitoringdevice in the esophagus. In embodiments where visualization of the innersurface of the esophagus comprises capturing video images, the positionsensor or the position reference feature may cause a mark (e.g., a depthinterval mark, a depth mark, etc.) to be placed on the video image tosynchronize the depth, or location, of the esophageal monitoring devicein the esophagus with the images shown in the video. In any event,position reference monitoring may enable correlation of the images ofthe inner surface of the esophagus to their relative positions along thelength of the esophagus.

In embodiments where visualization of the esophagus occurs whileintroducing the esophageal monitoring device into the esophagus, theimages obtained by such visualization may provide a baseline, orreference, for subsequent comparison. Thus, by comparing the imagesobtained after the ablation procedure, which may be referred to as“after images,” to the images obtained before the ablation procedure,which may be referred to as “before images,” a healthcare provider(e.g., a physician, a physician's assistant, etc.) can identify any newtrauma to the inner surface of the esophagus during the left atrialablation procedure, while introducing the esophageal monitoring deviceinto the esophagus, or while removing the esophageal monitoring devicefrom the esophagus. In some embodiments, light may be used to facilitatevisualization of the inner surface of the esophagus. So-called “whitelight” (i.e., a combination of various colors of visible light) may beused to illuminate the dark spaces and surfaces within the esophagus.Various wavelengths of electromagnetic radiation (e.g., ultravioletradiation, infrared radiation, etc.) may be used to reveal trauma orevidence of trauma (e.g., increased blood flow to a particular location,etc.) before it would otherwise be visible when illuminated with whitelight.

The monitoring that occurs during the left atrial ablation procedure mayprovide some indication of the danger of the ablation procedure to theesophagus. In some embodiments, temperature may be monitored across theinner surface of the portion of the esophagus located adjacent to theposterior wall of the left atrium. Temperature monitoring may occur at aplurality of locations (e.g., arranged in an area array, etc.) acrossthe area of the inner surface of the portion of the esophagus locatedadjacent to the posterior wall of the left atrium. Such temperaturemonitoring may occur in real-time throughout the left atrial ablationprocedure (e.g., frequently, continuously, etc.). By monitoring thetemperature of the esophagus, a healthcare provider may be able toreadily determine whether or not the left atrial ablation procedure isheating the esophagus to a potentially damaging temperature and, thus,inform the healthcare provider when one or more affirmative actions(e.g., temporary termination of ablation, reducing the force of theablation catheter against the interior surface of the left atrium,movement of the esophagus away from the left atrium, etc.) should betaken to prevent damage to the esophagus.

In the event that visualization of the inner surface of the esophagusafter a left atrial ablation procedure has been performed on theposterior wall of the left atrium of a subject's heart reveals that theesophagus has been traumatized or damaged, a healthcare professional maydiagnose and treat the damage. Such treatment may be providedimmediately following the left atrial ablation procedure or shortlyafter the left atrial ablation procedure (e.g., within one day of theleft atrial ablation procedure, within two days of the left atrialablation procedure, etc.). In some cases, visualization of the interiorsurfaces of the esophagus in connection with a left atrial ablationprocedure may enable healthcare professionals to treat damage to theesophagus before the subject experiences any adverse symptoms from theleft atrial ablation procedure.

Another embodiment of monitoring may include monitoring pressure orforce across the inner surface of the portion of the esophagus locatedadjacent to the posterior wall of the left atrium. More specifically,the force of the esophageal monitoring device against the wall of theesophagus may be monitored and/or the force of the esophagus against theesophageal monitoring device may be monitored. Even more specifically,the amount of pressure applied against the esophageal monitoring deviceby the inner surface of the relevant portion of the esophagus (i.e., theportion of the esophagus in proximity to the left atrium of the heart)may be monitored. Pressure monitoring may occur at a plurality oflocations (e.g., arranged in an area array, etc.) across the area of theinner surface of the portion of the esophagus located adjacent to theposterior wall of the left atrium. Such pressure monitoring may occur inreal-time, frequently throughout the ablation procedure or continuouslythroughout the left atrial ablation procedure. Pressure monitoring mayalso occur before and/or after the ablation procedure). Monitoring thepressure or the force applied by the esophageal wall to the esophagealmonitoring device may be used to provide an indication of the potentialor actual effects that the application of force by the ablation catheterto the interior surface of the left atrium and/or of the application offorce by the esophageal monitoring device against the esophageal wall onthe proximity of the esophagus to the left atrium, on the pressure orforce between the left atrium and the esophagus (although such pressureor force is indirect as it is applied directly against the pericardium)and, thus, on the potential for damage to the esophagus during the leftatrial ablation procedure. As a specific, but non-limiting example,monitoring the pressure or force applied to the esophageal monitoringdevice by the inner surface of the portion of the esophagus locatedadjacent to the posterior wall of the left atrium may indicate whetheror not the individual performing the left atrial ablation procedure isforcing the posterior wall of the left atrium toward the outer surfaceof the esophagus and, thus, increasing the likelihood that potentiallydamaging temperatures (e.g., heat or cold) would be transmitted from theleft atrium to the esophagus.

A system for monitoring a condition of a subject's esophagus while anablation procedure is being performed on the posterior wall of the leftatrium of the subject's heart includes an esophageal monitoring devicecapable of providing images of an inner surface of the esophagus. Morespecifically, the esophageal monitoring device may include a proximalelement, a monitoring element at a distal end of the proximal element,and a camera (e.g., a CMOS (complementary metal-oxide semiconductor)imager, a CCD (charge-coupled device camera), etc.). Optionally, theesophageal monitoring device may include an insertion component thatfacilitates insertion of the monitoring element into the esophagus, andthat may facilitate withdrawal of the monitoring element from theesophagus.

The proximal element of the esophageal monitoring device may comprise anelongated element. The proximal element may carry various features(e.g., proximally located electrical connectors, wires, electricaltraces, etc.) that enable the communication of signals betweencorresponding features at or near a distal end of the esophagealmonitoring device (e.g., temperature sensors and/or pressure sensors orforce sensors of the monitoring element, the camera, one or more lights(LEDs (light-emitting diodes), etc.), etc., within the subject'sesophagus) and equipment connected to a proximal end of the proximalelement (e.g., monitors and other devices outside of the subject'sbody). These features may be carried by (e.g., laminated onto,integrally formed with, etc.) a substrate of the proximal element.

The monitoring element of the esophageal monitoring device may belocated at a distal end of the proximal element. In various embodiments,the monitoring element may have a width or may be capable of assuming anexpanded width; i.e., a width that exceeds a width of the proximalelement. In some embodiments, the expanded width of the monitoringelement may effectively impart the monitoring element with an area thatis about the same as or larger than the area of a portion of theesophagus located adjacent to the posterior wall of the left atrium ofthe heart (e.g., at least about 58 mm by at least about 14 mm, or atleast about 812 mm²; about 60 mm by about 15 mm, or about 900 mm²; about70 mm by about 18 mm, or about 1,260 mm²; about 100 mm by about 20 mm,or about 2,000 mm²; etc.). Sensors may be positioned across an areaoccupied by the monitoring element. The sensors may include temperaturesensors, pressure sensors and/or force sensors, or a combinationthereof. In some embodiments, positional markers of the type used inanatomic mapping (e.g., impedance electrodes used in impedance-basedanatomical mapping, etc.) may also be positioned across an area occupiedby the monitoring element.

In a specific embodiment, the monitoring element may include a pluralityof branches that may be oriented somewhat parallel to one another,substantially parallel to one another, or parallel to each other. Evenmore specifically, the monitoring element may include three branches,with a center branch being collinear with, or even an extension of, theproximal element of the esophageal monitoring device. The branchesdiverge from the proximal element of the esophageal monitoring device ata proximal end of the monitoring element; the separate free ends of thebranches are located at a distal end of the monitoring element.

The branches of the monitoring element may be capable of being folded,one atop another. For example, the branches may be folded upon oneanother into a retracted arrangement while the monitoring elementresides within the lumen of the insertion component, but unfold as themonitoring element is deployed, or extends, distally beyond the distalend of the insertion component. Conversely, the distal end of theinsertion component and a proximal end of the monitoring element may bemutually configured to enable the branches of the monitoring element tofold upon one another as the esophageal monitoring device is pulledproximally and the monitoring element is pulled proximally back into theinsertion component.

When the monitoring element is in an expanded (e.g., deployed, unfolded,etc.) configuration, it may occupy an area that is about the same as orlarger than the area of a portion of the esophagus located adjacent tothe posterior wall of the left atrium of the heart (e.g., at least about58 mm by at least about 14 mm, or at least about 812 mm²; at least about70 mm by at least about 18 mm, or at least about 1,260 mm²; etc.). In aspecific embodiment, the area occupied by the expanded monitoringelement may be about 60 mm by about 15 mm, or about 900 mm². In anotherspecific embodiment, the area occupied by the expanded monitoringelement may be about 70 mm by about 18 mm, or about 1,260 mm². In yetanother specific embodiment, the area occupied by the expandedmonitoring element may be about 100 mm by about 20 mm, or about 2,000mm².

The area occupied by the branches of the monitoring element may besubstantially two-dimensional. Alternatively, the branches of themonitoring element may be arranged to occupy a three-dimensional space.For example, the branches of the monitoring element may be bent orcurved and arranged in a manner that enables them to be placed againstan interior surface of a subject's esophagus without requiring that aremainder of the esophageal monitoring device or the insertion componentbe forced against an internal surface of the esophagus. As anotherexample, the branches of the monitoring element may be arranged in amanner that approximates a shape or curvature of the interior surface ofthe esophagus against which they are to be placed.

Each branch of the monitoring element carries a plurality of sensors(e.g., temperature sensors, pressure sensors or force sensors, etc.).Optionally, each branch of the monitoring element may also carry one ormore positional markers (e.g., impedance electrodes used inimpedance-based anatomical mapping, etc., which may be used tothree-dimensionally map the location of the monitoring element withinthe esophagus and relative to the left atrium of the subject's heartand, when used in conjunction with measurements of the pressure or forceexerted on pressure sensors or force sensors of the monitoring element,may be used to map the physical relationship between the left atrium andthe esophagus, as well as any changes to that physical relationship(e.g., force of the left atrium against the pericardium, which is thentransmitted to the esophagus, etc.)). When the branches are positionedlaterally adjacent to one another, the sensors and positional markers,if any, may be positioned across an area occupied by the branches of themonitoring element. With the monitoring element in an expandedconfiguration, the sensors and positional markers, if any, carried byits branches may be spread over the area occupied by the monitoringelement. In some embodiments, the sensors and markers, if any, may bearranged in one or more arrays across the area occupied by themonitoring element. The monitoring element of the esophageal monitoringdevice may also carry a camera, one or more lights, etc., as describedpreviously herein.

In embodiments of the esophageal monitoring device that include aninsertion component, the insertion component may comprise a tube, acatheter, or a similar structure. At least a portion of the esophagealmonitoring device may be disposed within the insertion component (e.g.,a lumen thereof, a channel thereof, etc.) as that portion of theesophageal monitoring device is introduced into a subject's esophagus.In addition, the insertion component may be configured to enable theesophageal monitoring device to be pushed distally therethrough,enabling a distal portion of the esophageal monitoring device, such asthe monitoring element thereof, to be deployed from the distal end ofthe insertion component. In embodiments where the monitoring elementincludes three branches, the side branches may be folded over the centerbranch and over each other.

The proximal element and the monitoring element of the esophagealmonitoring device may have any suitable construction. In a specificembodiment, the proximal element and the monitoring element of theesophageal monitoring device may comprise a flexible printed circuitboard, or “flex PCB” or “flex circuit” that carries conductive traces,or “wires,” contacts, sensors, and other optional components (e.g., acamera, one or more lights, positional markers, etc.).

A system for monitoring a condition of a subject's esophagus during aleft atrial ablation procedure may also include an insertion component,such as a catheter or another tube, with a lumen within which at least aportion of the esophageal monitoring device may be disposed as thatportion of the esophageal monitoring device is introduced into asubject's esophagus. The insertion component may be configured to enablea distal portion of the esophageal monitoring device, such as thecamera, to protrude therefrom. In addition, the insertion component maybe configured to enable the esophageal monitoring device to be pusheddistally therethrough, enabling a distal portion of the esophagealmonitoring device, such as the monitoring element thereof, to bedeployed distally from the distal end of the insertion component.

In embodiments where the monitoring element includes branches, thebranches may be folded upon one another while the monitoring elementresides within the lumen of the insertion component, but unfold as themonitoring element is deployed, or extends, distally beyond the distalend of the insertion component. Conversely, the distal end of theinsertion component and a proximal end of the monitoring element may bemutually configured to enable the branches of the monitoring element tofold upon one another as the esophageal monitoring device is pulledproximally and the monitoring element is pulled proximally back into theinsertion component.

In some embodiments, the camera of the system may be positioned at oradjacent to a distal end of the esophageal monitoring device. Morespecifically, the camera of the system may be positioned at or adjacentto a distal end of the monitoring element of the esophageal monitoringsystem. In embodiments where the monitoring element is branched, thecamera may be positioned at or adjacent to a distal end of a centralbranch of the monitoring element. The camera may be capable of capturinghemispherical images of the esophagus (e.g., 120° hemispherical images,150° hemispherical images, 120° to 150° hemispherical images, up to 180°hemispherical images, 120° to 180° hemispherical images, etc.) orcylindrical images of the esophagus (e.g., a panoramic, or 360°, view,etc.). Thus, some embodiments of the camera may include a hemisphericallens (e.g. a fisheye lens, etc.) or a cylindrical lens (e.g., panoramiclens, etc.).

A system according to this disclosure may also include a light source. Alight source may illuminate the esophagus while obtaining images of theinner surface of the esophagus with the camera. The light source mayemit one or more wavelengths of visible light, including so-called“white light,” and/or one or more wavelengths of electromagneticradiation (e.g., ultraviolet radiation, infrared radiation, etc.) may beused to reveal trauma or evidence of trauma (e.g., increased blood flowto a particular location, etc.) before it would otherwise be visiblewhen illuminated with white light.

A system for monitoring a condition of a subject's esophagus accordingto this disclosure may include one or more position sensors. Theposition sensor(s) may be adapted to be placed at a fixed locationrelative to a path along which the esophageal monitoring device will beinserted into and removed from the subject's esophagus (e.g., along alength of an insertion component from which the esophageal monitoringdevice will be deployed, etc.). As a non-limiting example, a positionsensor may be capable of placement adjacent to a subject's nares ormouth, past which the esophageal monitoring device will pass as theesophageal monitoring device is inserted into or removed from thesubject's esophagus. As the esophageal monitoring device or featuresthereof (e.g., position reference features detectable by the positionsensor(s), etc.) move past the position sensor(s), the positionsensor(s) may determine an extent to which (e.g., a distance, etc.) theesophageal monitoring device has been inserted into the subject'sesophagus. Thus, each position sensor may also be used to determine alocation of a distal end of the esophageal monitoring device within theesophagus, or a distance the distal end of the esophageal monitoringdevice has been inserted into the esophagus. From such information, theposition sensor(s) may also determine a position of the camera from atop of the esophagus.

In embodiments where the system includes one or more position sensors,the esophageal monitoring device may include position referencefeatures. The position reference features may be disposed along a lengthof a portion of the esophageal monitoring device (e.g., along a proximalelement of the esophageal monitoring device, etc.). Alternatively,position reference features may be disposed along the length of aninsertion component for the esophageal monitoring device. Adjacentposition reference features may be spaced apart from one another at afixed distance, or interval. In a specific embodiment, adjacent positionreference features may be spaced 5 mm apart from one another. In anotherspecific embodiment, adjacent position reference features may be spaced1 cm apart from each other. The position reference features may bedetectable by a position sensor of a known type, which may be placed ata fixed location adjacent to the esophageal monitoring device as theesophageal monitoring device is introduced into or withdrawn from asubject's esophagus.

In another aspect, esophageal monitoring devices are disclosed.

Other aspects, as well as features and advantages of various aspects, ofthe disclosed subject matter will become apparent to those of ordinaryskill in the art through consideration of the ensuing description, theaccompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a diagram depicting the arrangement of the left atrium of theheart and the esophagus of a subject;

FIGS. 2 and 3 depict an embodiment of an esophageal monitoring systemaccording to this disclosure;

FIG. 4 shows a distal portion of an embodiment of an insertion componentof an esophageal monitoring system according to this disclosure, with adistal feature of an embodiment of an esophageal monitoring deviceprotruding from a distal end of the insertion component;

FIG. 5 shows the esophageal monitoring device within a lumen of theinsertion component;

FIG. 6 provides a top view of the distal portion of the embodiment ofinsertion component shown in FIG. 4 , with a monitoring element of theesophageal monitoring device partially deployed from the insertioncomponent;

FIG. 7 is a side view illustrating the monitoring element of theesophageal monitoring device fully deployed from the insertion componentand occupying a substantially two-dimensional area;

FIG. 8 is a top view of the arrangement illustrated by FIG. 7 ;

FIG. 9 is a perspective view of the arrangement illustrated by FIG. 7 ;

FIG. 10 illustrates another embodiment of an esophageal monitoringsystem according to this disclosure, including a proximal portion of anesophageal monitoring device and an insertion component over a remainderof the esophageal monitoring device;

FIG. 11 shows a monitoring element of the esophageal monitoring devicewithin a distal portion of the insertion component;

FIG. 12 is a side view of the esophageal monitoring system shown in FIG.11 , with the insertion component pulled proximally over an elongatedelement of the proximal portion of the esophageal monitoring device,adjacent to or against a handle of the proximal portion, and themonitoring element of the esophageal monitoring device in a deployedorientation;

FIG. 13 is a top view of the arrangement shown in FIG. 12 ;

FIG. 14 is an enlarged rear view of the embodiment of monitoring elementshown in FIG. 13 ;

FIG. 15 is a perspective view of a concave side of the embodiment ofmonitoring element shown in FIG. 13 ;

FIG. 16 is a perspective view of a convex side of the embodiment ofmonitoring element shown in FIG. 13 ;

FIG. 17 is a graph showing the time in which temperature sensors of theembodiment of esophageal monitoring device shown in FIGS. 10-16 respondto changes in temperature, and providing a comparison of that time tothe times in which temperature sensors of existing devices respond tochanges in temperature;

FIG. 18 illustrates an embodiment of a camera of an esophagealmonitoring device; and

FIGS. 19 and 20 illustrate embodiments of position sensors and positionmonitoring features of an esophageal monitoring system, which arecapable of monitoring the distance the esophageal monitoring device hasbeen inserted into the esophagus and, thus, its position along theesophagus.

DETAILED DESCRIPTION

FIGS. 2 and 3 illustrate an embodiment of a system 10 according to thisdisclosure, which system 10 may also be referred to as an “esophagealmonitoring system.” The system 10 is capable of monitoring a conditionof a subject's esophagus while an ablation procedure is being performedon the posterior wall of the left atrium of the subject's heart (i.e.,during a left atrial ablation procedure). As illustrated, the system 10includes an insertion component 20, an esophageal monitoring device 30,a camera 40, a position sensor 50, and a monitor 60.

In FIG. 2 , the esophageal monitoring device 30 is located within alumen 21 (FIG. 5 ) of the insertion component 20, but the camera 40,which is located on a distal end 32 (FIG. 6 ) of the esophagealmonitoring device 30, may be located at or just outside of (i.e., distalto) the distal end 22 of the insertion component 20.

In FIG. 3 , a monitoring element 34 of the esophageal monitoring device30 has been deployed from a distal end 22 of the insertion component 20,and branches 35 a, 35 b, 35 c of the monitoring element 34 haveexpanded.

The monitor 60 of a system 10 according to this disclosure may include adisplay screen 62, a processing element 64, and one or more connectors66 (e.g., communication ports, etc.).

A connector 66 of the monitor 60 may be configured to couple to, or matewith, a complementary connector of the esophageal monitoring device 30(e.g., the connector 26′ shown in FIGS. 10 and 12 , etc.). The connector66 may comprise any suitable communication port (e.g., a USB (universalserial bus) port, a USB-C port, a proprietary communication port, etc.).

The processing element 64 of the monitor 60 may, under control of one ormore programs or applications (or “apps”), communicate with variousdevices carried by the esophageal monitoring device 30, including thecamera 40, and the position sensor 50 (e.g., receive signals and dataembodied by the signals from devices carried by the esophagealmonitoring device 30 and the position sensor 50, send instructions todevices carried by the esophageal monitoring device 30, etc.). Inaddition, the processing element 64 may process data conveyed as signalsfrom devices carried by the esophageal monitoring device 30 and outputsuch data to the display screen 62 of the monitor 60. The processingelement 34 may comprise a central processing unit (CPU), a graphicsprocessing unit (GPU), a dedicated microcontroller, or the like.

The display screen 62 of the monitor 60 may function under control ofthe processing element 64 to provide one or more users (e.g., one ormore healthcare providers, etc.) with the data in a readilycomprehendible form (e.g., as numbers, graphics, etc.). As an example,the display screen 62 may display temperature data in numeric format, aswell as in colors to indicate whether or not the displayed temperaturevalues are potentially damaging to a subject's esophagus. As anotherexample, the display screen 62 may display a position of a monitoringelement 34 of the esophageal monitoring device 30 within a subject'sesophagus. The display screen 62 may, in some embodiments, provide auser of the system 10 with information about the pressure, or force,between the monitoring element 34 of the esophageal monitoring device 30and the wall of the esophagus against which the monitoring element 34 ispositioned, as well as an interpretation of the potential causes, theactual causes, the potential effects, and/or the actual effects of suchpressure.

In addition, the monitor (e.g., a touch-sensitive display screen 62,etc.) may enable a user to provide inputs that control operation of themonitor 60 and/or the esophageal monitoring device 30.

The insertion component 20 of the system 10 may be capable offacilitating introduction of the esophageal monitoring device 30 into asubject's esophagus, deploying the monitoring element 34 of theesophageal monitoring device 30, retracting the monitoring element 34 ofthe esophageal monitoring device 30 (e.g., into the insertion component20, etc.), and/or removing the esophageal monitoring device 30 from thesubject's esophagus. The insertion component 20 may comprise a flexiblecatheter or another flexible tubular element. That includes a distal end22 (e.g., the end that is to be introduced into the esophagus first), aproximal end 24 configured to remain outside of the subject's body, anda lumen 21 (FIG. 5 ) extending between the distal end 22 and theproximal end 24. Dimensions of the lumen 21 (e.g., its inner diameter)enable it to receive the esophageal monitoring device 30, including themonitoring element 34 of the esophageal monitoring device 30 when themonitoring element 34 is in a retracted arrangement.

An actuator 25 may be associated with a proximal end 24 of the insertioncomponent 20 and/or a proximal end of the esophageal monitoring device30 to enable a user (e.g., a healthcare provider, etc.) to control therelative positions of the insertion component 20 and the esophagealmonitoring device 30. In some embodiments, the actuator 25 may enable auser to slide the insertion component 20 along a length of theesophageal monitoring device 30. In other embodiments the actuator mayenable a user to slide the esophageal monitoring device 30 through thelumen 21 (FIG. 5 ) of the insertion component 20. As shown, the actuator25 may comprise an enlarged feature, or a handle, that may be graspedand moved by the user.

FIGS. 4 and 5 illustrate a distal portion of the insertion component 20,with FIG. 4 showing an exterior of the insertion component 20 and thecamera 40 protruding from the distal end 22 of the insertion component20, and FIG. 5 showing features of the esophageal monitoring device 30,including the monitoring element 34 thereof and a portion of a proximalelement 33 thereof.

In the illustrated embodiment, position reference features 28 arepositioned at fixed intervals along the length of the insertioncomponent 20. The position reference features 28 may be detectable bythe position sensor 50 as they pass by (or through) the position sensor50. The position sensor 50 may send signals to the processing element 64of the monitor 60, which may then determine a location of the insertioncomponent 20 and/or a distal portion of the esophageal monitoring device30 (e.g., its distal end, the monitoring element 34, etc.) relative tothe position sensor 50 and the esophagus (e.g., a distance the insertioncomponent and/or the esophageal monitoring device 30 has/have beeninserted into the esophagus, etc.).

FIGS. 6-9 show the monitoring element 34 of the esophageal monitoringdevice 30 deployed from the distal end 22 of the insertion component 20,with FIG. 6 providing a top view prior to unfolding of branches 35 a, 35b, 35 c, etc., of the monitoring element 34, FIG. 7 showing a side viewof a branch 35 a, and FIGS. 8 and 9 showing the branches 35 a, 35 b, 35c, etc., in a deployed, or an unfolded, arrangement. As illustrated byFIGS. 7 and 9 , the deployed monitoring element 34 may be substantiallytwo-dimensional.

The branches 35 a, 35 b, 35 c, etc., of the monitoring element 34 of theesophageal monitoring device 30 may be continuous with the proximalelement 33 of the esophageal monitoring device 30. In some embodiments,the proximal element 33 and the monitoring element 34 may comprise aflexible printed circuit board, or “flex PCB” or “flex circuit” thatcarries conductive traces, or “wires,” as well as electrical contacts.The branches 35 a, 35 b, 35 c, etc., of the monitoring element 34 mayalso include a structural support element 35 s (FIG. 7 ) which mayenable the branches 35 a, 35 b, 35 c, etc., to maintain or substantiallymaintain their relative positions when the monitoring element 34 and itsbranches 35 a, 35 b, 35 c, etc., are in their deployed arrangement. Thestructural support element 35 s may be carried by (e.g., laminated orotherwise secured to, formed within, etc.) the substrate of each branch35 a, 35 b, 35 c, etc. (e.g., the flex circuit, etc.). In a specificembodiment, the structural support element 35 s may comprise apre-shaped elongated element formed from a shape memory alloy, such asnitinol (or NiTiNOL—nickel-titanium Naval Ordnance Laboratory), whichmay assume its intended shape as the structure support element 35 s isdeployed from the lumen 21 (FIG. 5 ) of the insertion component 20 andexposed to the temperature within the esophagus (e.g., body temperature,etc.). In a more specific embodiment, the structural support element maycomprise a 0.008 inch diameter nitinol wire.

FIGS. 8 and 9 also illustrate an arrangement of sensors 38 and 39carried by the branches 35 a, 35 b, 35 c of the monitoring element 34and arranged across an area occupied by the monitoring element 34.Sensors 38 may comprise temperature sensors of a known type (e.g.,thermistors, etc.). Sensors 39 may comprise pressure sensors or forcesensors of a known type. In some embodiments, the monitoring element 34may carry sensors 39 that serve as positional markers (e.g., impedanceelectrodes, etc.), which may be used to anatomically map (e.g.,three-dimensionally map, etc.) the location of the monitoring element 34within the esophagus and relative to the left atrium of the subject'sheart (e.g., by impedance-based mapping, etc.) and, when used inconjunction with measurements of the pressure or force exerted onpressure sensors or force sensors of the monitoring element 34, may beused to map the physical relationship between the left atrium and theesophagus, as well as any changes to that physical relationship (e.g.,force of the left atrium against the pericardium and the esophagus,etc.).

Turning now to FIGS. 10-16 , another embodiment of a system 10′ formonitoring a condition of a subject's esophagus during a left atrialablation procedure is depicted. The system 10′ may include all of thecomponents of system 10 (FIGS. 2-9 ) (i.e., an insertion component 20′,a handle 25′ at a proximal end 24 of the insertion component 20′, anesophageal monitoring device 30′ within a lumen (not shown) of theinsertion component 20′, a camera 40′ at or near a distal end of theesophageal monitoring device 30′, an optional light source, a positionsensor 50 (FIGS. 2 and 3 ), and a monitor 60 (FIGS. 2 and 3 ), with theconfiguration of the esophageal monitoring device 30′ being the primarydifference between system 10′ and system 10 (FIGS. 2 and 3 ).

In particular, as depicted by FIGS. 12, 15, and 16 , the monitoringelement 34′ of the esophageal monitoring device 30′ may occupy athree-dimensional space rather than having a substantiallytwo-dimensional arrangement. More specifically, the branches 35 a′, 35b′, 35 c′, etc., of the monitoring element 34′ are bent or curved. Asdepicted by FIG. 15 , a structure support element 35 s carried by thesubstrate (e.g., a flex circuit, etc.) of each branch 35 a′, 35 b′, 35c′, etc., (e.g., an elongated element formed from a shape memory alloy,such as nitinol, a nitinol wire (e.g., a 0.008 inch diameter nitinolwire, etc.), a thin nitinol band, etc.) may define the shape of eachbranch 35 a′, 35 b′, 35 c′, etc., (e.g., as it is exposed to anincreased temperature (e.g., body temperature, etc.) within theesophagus, etc.) and the relative positions of the branches 35 a′, 35b′, 35 c′, etc., when they are deployed from the lumen 21 of theinsertion component 20′. The branches 35 a′, 35 b′, 35 c′, etc., may bebent or curved and arranged in a manner that facilitates their placementagainst an interior surface of a subject's esophagus. FIG. 16illustrates a convex side 37R′ of the monitoring element 34, which isconfigured to be positioned against the interior surface of theesophagus, while FIG. 15 illustrates a concave side 37F′ of themonitoring element 34′, which is configured to face into a lumen of theesophagus when the monitoring element 34′ is positioned against theinterior surface of the esophagus. In some embodiments, as themonitoring element 34′ is deployed in a subject's esophagus and placedagainst an interior surface of the esophagus, the branches 35 a′, 35 b′,35 c′, etc., may flatten out, enabling the monitoring element 34′ to beplaced against the interior surface of the esophagus without deformingor moving the esophagus.

As shown in FIGS. 14 and 16 , sensors 38′, 39′ may be carried by theconcave side of each branch 35 a′, 35 b′, 35 c′, etc., of the monitoringelement 34′ (i.e., the side that will be placed against an interiorsurface of the subject's esophagus).

Due to the low thermal mass of flexible printed circuit boards, theiruse as the substrate for a monitoring element 34′, or for each branch 35a′, 35 b′, 35 c′, etc., of the monitoring element 34′, dramaticallyincreases the thermal response time of each temperature sensor (e.g.,each sensor 38′). The temperature sensors (e.g., sensors 38′) of themonitoring element 34′ of the esophageal monitoring device 30′ respondto temperature changes within 0.1 second (i.e., one-tenth of a second orless). By way of comparison, the temperature sensors of the CIRCAS-CATH™ esophageal temperature monitor available from CIRCA Scientific,LLC, of Englewood, Calif., respond to temperature changes in about two(2) seconds while it takes about eight (8) seconds for the temperaturesensors of a general purpose esophageal probe to respond to temperaturechanges. These response times are illustrated by the graph of FIG. 17 ,in which twelve (12) response times were measured and averaged fortemperature sensors of the monitoring element 34′ of the esophagealmonitoring device 30′ (the left-most curve) and compared with averageresponse times for temperature sensors of the CIRCA S-CATH™ esophagealtemperature monitor (the center curve), and the Level 1® 9 F generalpurpose esophageal/rectal temperature probe available from SmithsMedical of Dublin, Ohio (the right-most curve). In those response timeanalyses, temperature sensors that had been heated to a temperature of36° C. (e.g., in a warm water bath, etc.) were immersed in a warmer, 40°C. water bath, and the amount of time it took each sensor to respond toa 2° C. rise in temperature (from 36° C. to 38° C.) was measured.

By providing quick response times to changes in temperature, anesophageal monitoring device (e.g., esophageal monitoring device 30′,etc.) according to this disclosure may enable a healthcare provider toreact more quickly to the exposure of the esophagus to potentiallydamaging temperatures. Improvement of the healthcare provider's reactiontimes may decrease the likelihood of damage to the esophagus during aleft atrial ablation procedure.

FIG. 18 provides a close-up view of a camera 40, which is located at adistal end 36 b of a branch 35 b of the monitoring element 34 of theesophageal monitoring device 30 (or at a distal end of a branch 35 b′ ofthe monitoring element 34′ of the esophageal monitoring device 30′). Asillustrated, the camera 40 may include a lens 42 with a dome shape, ahemispherical shape, or any other shape that will enable the camera 40to capture images around an entirety of the inner surface of theesophagus. A light source (e.g., a source of visible light, a source ofinfrared radiation, a source of ultraviolet radiation, etc.) may beassociated with the camera 40 to enable or enhance visualization of theinterior surface of the esophagus.

With reference to FIG. 19 , an embodiment of use of the position sensor50 and the position reference features 28 on the insertion element 20 isdepicted. In particular, FIG. 19 depicts the use of the position sensor50 and the position reference features 28 while inserting the insertioncomponent 20 and, thus, the esophageal monitoring device 30 (FIGS. 2 and5-8 ) into a subject's esophagus. The position sensor 50 may be placedat a fixed location, such as the nares or mouth of the subject. As theinsertion component 20 is introduced into the esophagus, it passes by orpasses through the position sensor 50. The position sensor 50 may detecteach position reference feature 28 on the insertion component 20 thatpasses thereby or therethrough.

FIG. 20 illustrates use of the position sensor 50 and the positionreference features 28 as the insertion component 20 and, thus, theesophageal monitoring device 30 are withdrawn from a subject'sesophagus. Again, as each position reference feature 28 on the insertioncomponent 20 passes by or through the position sensor 50, the positionsensor 50 detects that position reference feature.

In use, the insertion component 20 may initially reside over themonitoring element 34 of the esophageal monitoring device 30, as shownin FIGS. 2, 4, and 5 . With the insertion component 20 and theesophageal monitoring device 30 in this arrangement, they may beintroduced into a subject's esophagus (e.g., through the subject's nose,through the subject's mouth, etc.). The position of the insertioncomponent 20 and/or the esophageal monitoring device 30 may be monitored(e.g., by the position sensor 50, etc.; see, e.g., FIG. 19 ) as they areintroduced into the esophagus. In addition, the interior surfaces of theesophagus may be visualized (e.g., with the camera 40, etc., with orwithout illumination) while the insertion component 20 and theesophageal monitoring device 30 are introduced into the esophagus.

Once the distal end 22 of the insertion component 20 has reached adesired location within the esophagus, the monitoring element 34 of theesophageal monitoring device 30 may be deployed from the lumen 21 of theinsertion component 20, as depicted by FIGS. 3 and 6-9 . In embodimentsof the system 10 where the insertion component 30 can be pulledproximally to deploy the monitoring element 34 of the esophagealmonitoring device 30, deployment of the monitoring element 34 may occuronce the distal end 22 of the insertion component 20 has been advancedto a location beneath a portion of the esophagus located in proximity tothe left atrium of the subject's heart. In embodiments where theesophageal monitoring device 30 can be pushed distally out of the distalend 22 of the insertion component 20, deployment of the monitoringelement 34 may occur once the distal end 22 of the insertion component20 has been advanced to a location just above a portion of the esophaguslocated in proximity to the left atrium of the subject's heart.

Once deployed, the monitoring element 34 may be placed against aninterior surface of the esophagus, at a location where the esophagus islocated closest to the left atrium of the subject's heart. Themonitoring element 34 or, more specifically, sensors carried by themonitoring element 34 (e.g., temperature sensors 38, force sensors 39,etc.) may be used to monitor the surface of the esophagus against whichthe monitoring element 34 has been placed. Such monitoring may occurduring a left atrial ablation procedure and, optionally, before the leftatrial ablation procedure (e.g., to provide baseline temperaturereadings, baseline pressure readings, etc.).

In addition, positional markers (e.g., impedance electrodes, etc.) maybe used to three-dimensionally map the location of the monitoringelement within the esophagus and relative to the left atrium of thesubject's heart. When used in conjunction with measurements of thepressure or force exerted on pressure sensors or force sensors 39 of themonitoring element 34, may be used to map the physical relationshipbetween the left atrium and the esophagus, as well as any changes tothat physical relationship (e.g., force of the left atrium against thepericardium and the esophagus, etc.).

Once the left atrial ablation procedure is complete, the monitoringelement 34 may be retracted back into the lumen 21 of the insertioncomponent 20, and the insertion component 20 and the esophagealmonitoring device 30 may be removed from the subject's esophagus. Theposition of the insertion component 20 and/or the esophageal monitoringdevice 30 may be monitored (e.g., by the position sensor 50, etc.; see,e.g., FIG. 20 ) as they are removed from the esophagus. In addition, theinterior surfaces of the esophagus may be visualized (e.g., with thecamera 40, etc., with or without illumination) while the insertioncomponent 20 and the esophageal monitoring device 30 are removed fromthe esophagus.

In embodiments where the interior surfaces of the esophagus have beenvisualized, a healthcare provider may analyze the interior surfaces todetermine whether or not the left atrial ablation procedure has damagedthe esophagus. Corrective measures (e.g., surgical treatment, medicaltreatment, etc.) may then be initiated immediately or within a shortperiod of time (e.g., one day, two days, etc.) of the left atrialablation procedure.

While the foregoing disclosure relates to esophageal monitoring devices,systems, and methods that are useful during left atrial ablationprocedures, the teachings provided herein may also be applicable todevices, systems, and methods for monitoring tissue temperatures duringother procedures where adjacent tissues are heated or cooled.

Although the foregoing description contains many specifics, these shouldnot be construed as limiting the scopes of the inventions recited by anyof the appended claims, but merely as providing information pertinent tosome specific embodiments that may fall within the scopes of theappended claims. Features from different embodiments may be employed incombination. In addition, other embodiments may also lie within thescopes of the appended claims. All additions to, deletions from, andmodifications of the disclosed subject matter that fall within thescopes of the claims are to be embraced by the claims.

What is claimed:
 1. A method for evaluating a state of an esophagusbefore, during, and after an ablation procedure conducted on a leftatrium of a heart, the method comprising: introducing an esophagealmonitoring device into the esophagus within an insertion component;further introducing a monitoring element of the esophageal monitoringdevice into the esophagus by deploying the monitoring element distallyfrom the insertion component; visualizing an inner surface of theesophagus while further introducing the monitoring element into theesophagus; conducting the ablation procedure within the left atrium ofthe heart; monitoring a condition of a portion of the inner surface ofthe esophagus adjacent to the left atrium of the heart while conductingthe ablation procedure; withdrawing the monitoring element through theesophagus by retracting the monitoring element into the insertioncomponent after conducting the ablation procedure; visualizing the innersurface of the esophagus, including the portion of the inner surface ofthe esophagus adjacent to the left atrium of the heart, whilewithdrawing the monitoring element through the esophagus; andwithdrawing the esophageal monitoring device, including the insertioncomponent and the monitoring element therein, from the esophagus.
 2. Themethod of claim 1, wherein: introducing the esophageal monitoring deviceinto the esophagus comprises: introducing a temperature probe carrying aplurality of temperature sensors in an area array into the esophagus;and positioning the temperature probe against the portion of the innersurface of the esophagus adjacent to the left atrium; and monitoring thecondition of the portion of the inner surface of the esophagus adjacentto the left atrium of the heart while conducting the ablation procedurecomprises: monitoring temperatures of the inner surface of the portionof the esophagus adjacent to the left atrium at a plurality of locationsadjacent to which the plurality of temperature sensors are positioned.3. The method of claim 2, wherein further introducing the monitoringelement into the esophagus further comprises: unfolding branches of thetemperature probe when the branches of the temperature probe are locatedadjacent to the portion of the esophagus adjacent to the left atrium. 4.The method of claim 1, wherein: further introducing the monitoringelement into the esophagus comprises: introducing a pressure probecarrying a plurality of pressure sensors in an area array into theesophagus; and positioning the pressure probe against the portion of theinner surface of the esophagus adjacent to the left atrium; andmonitoring the condition of the portion of the inner surface of theesophagus adjacent to the left atrium of the heart while conducting theablation procedure comprises: monitoring pressure applied to the portionof the inner surface of the esophagus adjacent to the left atrium of theheart by the left atrium at a plurality of locations adjacent to whichthe plurality of temperature sensors are positioned.
 5. The method ofclaim 4, wherein further introducing the monitoring element into theesophagus further comprises: unfolding branches of the pressure probewhen the branches of the pressure probe are located adjacent to theportion of the esophagus adjacent to the left atrium.
 6. The method ofclaim 1, wherein visualizing the inner surface of the esophagus whilefurther introducing the monitoring element into the esophagus and/orvisualizing the inner surface of the esophagus, including the portion ofthe inner surface of the esophagus adjacent to the left atrium of theheart, while withdrawing the monitoring element through the esophaguscomprises visualizing the inner surface of the esophagus at fixeddistance intervals.
 7. The method of claim 6, wherein visualizing theinner surface of the esophagus while further introducing the monitoringelement into the esophagus and/or visualizing the inner surface of theesophagus, including the portion of the inner surface of the esophagusadjacent to the left atrium of the heart, while withdrawing themonitoring element through the esophagus comprises visualizing the innersurface of the esophagus at intervals of about 5 mm.
 8. The method ofclaim 1, wherein visualizing the inner surface of the esophagus whilefurther introducing the monitoring element into the esophagus andvisualizing the inner surface of the esophagus, including the portion ofthe inner surface of the esophagus adjacent to the left atrium of theheart, while withdrawing the monitoring element through the esophaguscomprise obtaining a plurality of still images of the inner surface ofthe esophagus.
 9. The method of claim 1, wherein visualizing the innersurface of the esophagus comprises illuminating the inner surface of theesophagus with at least one wavelength of light that will reveal traumato the inner surface of the esophagus earlier than white light willreveal the trauma.
 10. The method of claim 1, further comprising:comparing a condition of the inner surface of the esophagus whilefurther introducing the monitoring element into the esophagus to acondition of the inner surface of the esophagus while withdrawing themonitoring element through the esophagus.
 11. The method of claim 10,wherein comparing comprises determining an effect of the ablationprocedure on the inner surface of the esophagus, including an innersurface of the portion of the esophagus located adjacent to the leftatrium of the heart.
 12. The method of claim 10, wherein comparingcomprises determining an effect of introducing the esophageal monitoringdevice into the esophagus and/or removing the esophageal monitoringdevice from the esophagus on the inner surface of the esophagus.
 13. Themethod of claim 10, further comprising: addressing any damage to theesophagus.
 14. A method for evaluating a state of an esophagus before,during, and after a medical procedure, the method comprising:introducing a monitoring element of an esophageal monitoring device intothe esophagus by deploying the monitoring element distally from aninsertion component of the esophageal monitoring device; visualizing aninner surface of the esophagus while further introducing the monitoringelement into the esophagus; conducting the medical procedure;withdrawing the monitoring element through the esophagus by retractingthe monitoring element into the insertion component after conducting themedical procedure; and visualizing the inner surface of the esophaguswhile withdrawing the monitoring element through the esophagus.
 15. Themethod of claim 14, further comprising: introducing the esophagealmonitoring device into the esophagus with the monitoring elementretracted into the insertion component.
 16. The method of claim 14,further comprising: monitoring a condition of a portion of the innersurface of the esophagus while conducting the medical procedure.
 17. Themethod of claim 14, further comprising: withdrawing the esophagealmonitoring device, including the insertion component and the monitoringelement, from the esophagus.
 18. The method of claim 14, furthercomprising: comparing a condition of the inner surface of the esophaguswhile further introducing the monitoring element into the esophagus to acondition of the inner surface of the esophagus while withdrawing themonitoring element through the esophagus.
 19. The method of claim 18,wherein comparing comprises determining an effect of the medicalprocedure on the inner surface of the esophagus.
 20. The method of claim18, wherein comparing comprises determining an effect of introducing theesophageal monitoring device into the esophagus and/or removing theesophageal monitoring device from the esophagus on the inner surface ofthe esophagus.